1
U.S. black bears are terrifying. North American black bears are brown bear subspecies. These medium-sized bears vary by location. Black bears eat plants and animals.
2
Mountain lions and pumas are also cougars. The jaguar is the largest U.S. wild cat. Cougars bite hard. They weigh 64–198 pounds. They can jump 20 feet to attack on prey from afar. These terrifying cats rarely attack people. Don't provoke them—they'll attack if threatened.
3
Sharks are scary, thus Jaws was a hit. Sharks, especially the terrifying great white, live in the U.S. Despite the vast population of these apex predators, fatal shark attacks are rare in the U.S. 82 shark attacks occurred in 2018. Florida and California had 64% of these attacks.
4
The shoe-button spider, or black widow, lives in temperate climates on every continent except Antarctica. Males are innocuous, but females bite toxically. Black widow males are eaten by larger females during mating. Males sometimes escape.
5
Diamondbacks, a copperhead, are one of the scariest animals in the US. These notorious reptiles have heat detectors on either side of their heads to see their environment. They clatter, but sometimes they're silent, so keep your eyes and ears open.
6
Gray wolves live in Oregon, California, Washington State, Montana, Idaho, Michigan, Wyoming, Wisconsin, Alaska, and Minnesota. However, human encroachment nearly destroyed these canines in the US.
7
American alligators are terrifying. These 1,000-pound reptiles are less violent than crocodiles. Territorial alligators rarely attack humans. They attack if provoked. They may also attack if food is scarce. Alligators' deadly jaws scare people.
8
America's largest and most dangerous animal is the American crocodile. These massive crocs live in Florida. Attacks are rare due to the limited American crocodile population. These crocs can hide and are aggressive.
9
When at full sail, the Portuguese Man O'War resembled an 18th-century Portuguese-armed ship, hence its name. Fish die from this creature's tentacles. It kills humans too. Water stings cause paralysis and drowning.
10
Timber rattlesnakes are terrifying. This threatening snake can murder people. It grows 3–7 feet long and has a dark zig-zag pattern and rough scales. Timber rattlesnakes inhabit the eastern U.S.